1. Field of the Invention
The present invention relates generally to bridge apparatus for stringed musical instruments, and more particularly to an improved bridge design which provides for a high degree of transmission of vibratory energy from each string directly to the sound board of the instrument.
2. Description of the Prior Art
The present invention is directed to bridges utilized in those types of instruments characterized by a resonant body or bell having a sounding board secured over the upper or outer side of the body with an elongated fingerboard-carrying neck having one end affixed to the body and an opposite end terminating in a head to which the string-tuning keys or pegs are mounted. In such instruments, spaced strings are secured to the head-mounted keys and are extended inwardly therefrom along and over the finger-board and then across the sounding board and a bridge positioned on the board to means for attaching the strings to the board. The sounding board is typically a thin sheet of wood provided with an opening or sound hole underlying the strings to permit the sound waves to enter the interior of the body which, acting as a resonating chamber, enriches the tone of the strings, this tone being further enriched by the vibration of the sounding board itself acting as a kind of diaphragm. Sonic energy is transferred directly from the strings to the soundboard by the bridge which is mounted to the upper surface thereof between the sound hole and the end of the body remote from the neck of the instrument.
Although there are numerous types and configurations of bridges known in the prior art, the bridge type toward which the present invention is directed is that which is usually formed of a thin, hand-crafted wooden or plastic slab after having a set of transverse grooves along one of its edges in which the strings are tautly held. In the case of banjos, and what are commonly referred to as flattop guitars, the bridge is sometimes mounted unattachedly upon the resonant diaphragm or soundboard of the instrument and is held in place by the strings.
Heretofore, bridge designs have focused on attempts to limit soundwave energy absorption and dissipation within the bridge itself, and to enhance the tonal clarity of the sounds transmitted by the bridge. Design attempts at achieving this goal have been directed principally at shaping the periphery of the bridge in complex manners on a trial and error basis. Such bridges have been both costly and difficult to reproduce, particularly with consistency.
One example of such a bridge is disclosed in the U.S. Pat. No. of Geiger (No. 4,899,634) which is comprised of a thin wooden body having a base portion adapted to be supported upon the sounding board of an instrument, and a top crown portion that is formed with grooves for holding the individual strings. The base and crown portions have mating edges that are generally parallel with respect to each other. The crown is formed with baffled slits located adjacent the grooves and oriented obliquely with respect to the crown edge for redirecting soundwaves emitted from the strings back to the grooves to produce a ringing effect to the base to reduce sound attenuation within the bridge. In a secondary embodiment, a bridge is formed of a plurality of discrete bridge segments which individually support the several strings of the instrument and are coupled together by safety strings. Although the approach of the principal embodiment of this patent seeks to improve the coupling between the five strings and the soundboard, it uses only three pedestals to do so, with sound from all but the center string being directed laterally to a pedestal rather than directly downward to the sounding board. The alternative embodiment appears to provide a better solution in that it provides single structures for coupling sound from each string to the soundboard. However, such approach suffers from problems relating to stability, maintenance of position, and other unfavorable characteristics.
Ancient attempts at providing solutions somewhat related to Applicants' solution are disclosed in the 1921 German Patent to Lauten et al., the 1961 Design Patent to Ressler, and the 1899 Patent to Kohl (No. 30,515). However, although having apparent similarities to the subject invention, none address the same problem or provide the same solution to the problem provided by the present application; namely, separation and simultaneous maximization of energy transfer from each string to the soundboard with a minimum of coupling between adjacent string support pedestals.